In regards to tracklists for albums related to the original game, is 'Varestain' an official romanization? All I know is that in the English language versions of the SNES and MD releases it's called 'Ballactine'. And since there's been a bit of editing back and forth it would be good if we could settle for one or the other.

Yeah, it was me who "fixed" the tracklists. And why I chose 'Varestain' over 'Valestein', 'Ballactine' or whatever translation of the term バレスタイン城 from the different versions of Ys III?
Well, THIS is the reason. As far I know, this is the only album in Falcom's history to give a translation of バレスタイン. So, a more official source than this I don't think you'll find it.